Short Message Service (SMS) text messaging is one of the most pervasive forms of communication and familiar to most users of Global System for Mobile Communication (GSM) and other telephone networks. In the simplest form of operation an SMS message is sent from one mobile user to another mobile user through a SMS Centre (SMSC).
SMS messages may be transmitted within the same mobile telephone network or to anyone with roaming service capability.
SMS messages maybe either text as conventionally employed by users or binary coded messages. There are many variations on the way an SMS message is encoded, both for encoding “text” messages and for encoding “binary” messages. Generally speaking and more particularly, in the context of the present application text messages refers to messages which represent human readable SMS messages. Binary messages refers to messages which are not intended to be read by a user on their phone, i.e. non human-readable messages, such as OTA (Over The Air configuration) messages, Wireless Application Protocol (WAP) PUSH messages, ringtones, etc. The normative reference is the 3rd Generation Partnership Project (3GPP) specification TS 23.040, currently at version 8.3.0 and available at www.3gpp.org.
The present application is directed at how SMS text messages are sent, delivered and stored.
Conventionally, SMS text messages are stored by SMSC's until the message has been delivered to a user. Once the message has been delivered or where delivery was not possible within a particular time period the message is deleted. The messages may be deleted once delivery is confirmed or periodically messages may be purged. As a result messages are only transiently stored at the SMSC.
Recently, services have been developed which extend the functionality of SMSC's or other devices within the mobile network so that SMS messages being received and sent by a user are intercepted. Once intercepted, the service can provide a value added service to the user. For example, a service may be provided which stores a copy of all messages received or sent by a user in a database. This database may then be accessed by a user, for example by means of a website, to review any message they have received or sent. Such a service is provided by O2 in the United Kingdom to its customers and marketed as BLUEBOOK™. Similarly, a SPAM or inappropriate text filter may be employed on intercepted SMS messages to prevent the delivery of such messages to a user. It will be appreciated that a variety of alternative services may also be provided using this technology.
Such services are facilitated by the use of home routing which would be familiar to those skilled in the art and provides that all messages received by a SMS user pass through their home SMSC or an associated router regardless of where the messages originate from. Where home routing is not employed, the benefits are less as the user's SMSC\router will not have full sight of all messages destined for the user.
Another development in the mobile phone environment is that availability of multi-SIM phone systems. In a multi-SIM configuration, a mobile user might have several phones with the same effective phone number. With telephone calls, the implementation of the system is relatively straightforward, in that if a user receives a call on a particular number, all of the phones associated with the particular number are rung and the phone which picks-up the call first is connected to the caller. At which time, the ringing on the other phones stops.
Messaging presents greater challenges. For example, consider the case of a user with two phones each associated with a common phone number, the first phone might be the personal mobile phone generally in the possession of the user, whereas the second phone might be a car phone. In a first mode of operation, the SMSC may send all messages to each phone separately. However, it will be clear in this situation; a user might receive and answer a number of messages on their phone in the office only later when entering their car to find the same messages waiting for them on their car phone. Obviously, this could be very confusing for a user. Accordingly, techniques are being developed which filter the destination of an SMS message using heuristic techniques to ascertain where the user is.
An alternative approach is that of Singtel who have a multi-sim product that requires the user to type\send a particular code to identify one mobile handset as the preferred handset for voice calls and SMS/Multi Media Messaging Service (MMS). Using these systems, the user only receives messages on one of their phones. However, it will be appreciated that this is a cumbersome system and means that a user viewing their messages on one phone will not have a message they received on the other phone. It also requires them to update their service continually.
The present application is directed at an alternative approach to handling SMS text messages.